Polyolefin Fiber Reinforced Concrete

摘要

This report documents preliminary results from an investigation of a new polymer fiber and unique delivery system for charging the fibers into concrete mixtures. The straight polyolefin fibers are 0.50-mm in diameter by 63-mm long and are packaged in bundles approximately 50-mm in diameter. Each bundle is encased with a water soluble tape. The bundles of fibers are charged into the concrete mixture in mass. Approximately 3 to 4 minutes of mixing is necessary to disperse the tape and distribute the fibers throughout the concrete. Fresh properties measured included slump, air content, unit weight, temperature, and vebe consistency. Hardened properties measured included compressive strength, flexural strength, flexural toughness, and impact resistance. The results indicate that the polyolefin fiber and charging system appear to be viable for producing fiber reinforcing concrete. Fiber loadings up to 15 kg/m~3 (1.65 percent volume) were evaluated. Concrete mixtures with the polyolefin fibers can be produced having adequate workability and finishability if proportioned properly. Addition of the polyolefin fibers does not significantly influence the compressive nor first-crack flexural strength of concrete mixtures. However the presence of the polyolefin fibers do influence the post crack behavior of concrete mixtures. Impact resistance and flexural toughness appear to increase as the fiber loading increases.